Resolution for autostereoscopic video displays

ABSTRACT

A single pixel of a video display can display respective individual pixels of multiple views. In other words, a video display can include more views for an autostereoscopic image than the physical pixels of the video display would ordinarily support. The physical pixel is time-multiplexed in that the physical pixel displays a pixel of one view for a given time interval and a view multiplexer deflects the light from the physical pixel by a predetermined angle to make the pixel appear in a location corresponding to the pixel of the view. In another time interval, the physical pixel displays a pixel of a different view and the view multiplexer deflects light from the physical pixel by a different predetermined angle to make the pixel appear in a location corresponding to the pixel of the different view.

FIELD OF THE INVENTION

The present invention relates generally to autostereoscopic displays,and, more particularly, to a video autostereoscopic display withsignificantly improved resolution.

BACKGROUND OF THE INVENTION

Conventional autostereoscopic displays use arrays of lenses or parallaxbarriers or other view selectors to make a number of pixels of thedisplay visible to one eye of a viewing person and to make a number ofother pixels of the display visible to the other eye of the viewingperson. By isolating the pixels of the display visible to each eye, thetwo components of a stereoscopic image can be presented on the display.

Since an ordinary viewer's eyes are side-by-side and alignedhorizontally, the array of lenses makes pixels visible according tohorizontal orientation. As a result, corresponding pixels for the leftand right eyes are located in the same scanline and displaced from oneanother horizontally.

Each eye of the viewer therefore sees an image whose horizontalresolution is halved in an autostereoscopic displays having only twoviews. In most autostereoscopic displays, field of view is improved byhaving more than just two views. In attempts to provide greaterperceived depths of projection, many more views—e.g., 24 views—arerequired within a relatively narrow space—e.g., 1 mm. A typical LCDdisplay screen has a pixel density of about 200 pixels per inch, thoughsome have densities approaching 300 pixels per inch. That'sapproximately 6 pixels per millimeter, i.e., about one quarter of theresolution required to provide 24 views in a 1 mm space.

Thus, conventional video display devices are incapable of providingenough views in a sufficiently small space to satisfy the demands ofmodern autostereoscopic images.

SUMMARY OF THE INVENTION

In accordance with the present invention, a single pixel of a videodisplay can display respective individual pixels of multiple views. Inother words, a video display can include more views for anautostereoscopic image than the physical pixels of the video displaywould ordinarily support.

To achieve multiple views with a single physical pixel, the physicalpixel is time-multiplexed. In particular, the physical pixel displays apixel of one view for a given time interval and a view multiplexerdeflects the light from the physical pixel by a predetermined angle tomake the pixel appear in a location corresponding to the pixel of theview. In another time interval, the physical pixel displays a pixel of adifferent view and the view multiplexer deflects light from the physicalpixel by a different predetermined angle to make the pixel appear in alocation corresponding to the pixel of the different view.

The view multiplexer includes a number of columnar prisms ofbirefringent material such that deflection of light passing through thecolumnar prisms is switchable between two different angles bycontrolling the polarity of the light passing through. Alternatively,the material of the columnar prisms varies its refraction indexaccording to an electrical field of the columnar prisms. An example ofsuch a material is liquid crystal. The controllability of the reflectionangles provided by the columnar prisms enables control of the locationat which a given pixel appears to be to a human viewer.

By synchronizing the location at which a given pixel appears to be andthe particular view displayed by the pixel allows that pixel to displaypixels of multiple views for respective fractions of a frame rate.Persistence of vision of the human viewer causes the one pixel of theone view that is visible to the viewer through the lenticular array tocontinue to be perceived for the entire frame.

Multiple view multiplexers can be stacked to provide a wider variety ofcumulative deflection angles.

In addition, focus errors due to curvature of field of the individuallenticles of a lenticular array are reduced by configuring the lenticlesto focus at an acceptable distance behind the target of focus, e.g., thepixels of the autostereoscopic display. The result is that, due tocurvature of field, the lenticles will focus particularly well atmoderate angles of viewing perspective and will still produce acceptablefocus errors and even wider angles of viewing perspective.

A BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a viewer and an autostereoscopic display inaccordance with the present invention.

FIG. 2 is a plan view of a portion of the autostereoscopic display ofFIG. 1 in greater detail.

FIG. 3 is a plan view of a view multiplexer of the autostereoscopicdisplay of FIGS. 1 and 2 in greater detail.

FIG. 4 is a timing diagram illustrating the time-multiplexing of a pixelusing two (2) view multiplexers in accordance with the presentinvention.

FIG. 5 is a plan view of an alternative autostereoscopic display inaccordance with the present invention.

FIG. 6 is a plan view of a portion of the autostereoscopic display ofFIG. 5 in greater detail.

FIG. 7 is a plan view illustrating focus of the autostereoscopic displayof FIGS. 5 and 6.

FIG. 8 is a plan view of an alternative view multiplexer in accordancewith the present invention.

FIGS. 9 and 10 are timing diagrams illustrating time-multiplexing of apixel using the view multiplexer of FIG. 8.

FIG. 11 is a plan view of the mask of FIG. 2 enlarged to illustratelocations of apparent pixels due to operation of view multiplexers ofFIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the present invention, a single pixel of a videodisplay can display respective individual pixels of multiple views. Inparticular, a stereoscopic display 100 (FIGS. 1 and 2) includes viewmultiplexers 204A-B (FIG. 2) that bend light from each of a number ofpixels, such as pixels 216A-F, such that each pixel appears to be at aslightly different location and represents a pixel of a different viewfor each of a number of multiple time intervals. For example, viewmultiplexers 204A-B can cause pixel 216A to be at any of locations 216A1(FIG. 11), 216A2, 216A3, and 216A4. In this manner, each of pixels216A-F is time-multiplexed to represent pixels of respective multipleviews of an autostereoscopic display.

In a manner described more completely below, view multiplexers 204A-Bcombine to provide 4-to-1 multiplexing in this illustrative embodiment.View multiplexers 204A-B bend light from pixels 216A-F at predetermined,fractional view angles at predetermined time intervals. In thisillustrative embodiment, lenticle 202C is designed to provide a viewangle increment of one degree, meaning that viewing perspectives throughlenticle 202C at which each of pixels 216A-F is viewable through a mask214 differ by one degree. To provide four (4) views from a single pixel,view multiplexers 204A-B combine to deflect light at four (4), evenlyspaced, fractional view angles, namely, 0 degrees, 0.25 degrees, 0.5degrees, and 0.75 degrees in this illustrative embodiment; other anglescan be used in other embodiments. It should be appreciated that a singleview multiplexer can provide two (2) views from a single pixel, three(3) view multiplexers can be combined to provide up to eight (8) viewsfrom a single pixel, and numerous other combinations can be implementedto provide even more views from a single pixel. It should be furtherappreciated that a view multiplexer can sweep across a range ofdeflection angles to provide other numbers of views from a single pixelin the manner described below.

Display of four (4) views using a single one of pixels 216A-F is shownin timing diagram 400 (FIG. 4). As described more completely below, viewmultiplexer 204A is switchable between deflecting light at 0.5 degreesor not deflecting light at all, and view multiplexer 204B is switchablebetween deflecting light at 0.25 degrees or not deflecting light at all.View multiplexers 204A-B switch at a rate of 120 Hz, and viewmultiplexer 204B follows view multiplexer 204. As by a lag of one-halfclock cycle as shown in timing diagram 400.

Pixels 216A-F have a refresh rate of 240 Hz. Initially in timing diagram400, view multiplexers 204A-B are both off, i.e., not deflecting light,and pixel 216A displays a pixel of view N for a single refresh cycle. Ifan eye of viewer 10 is aligned with pixel 216A through mask 214 andlenticle 202A, that eye will see view N of pixel 216A at location 216A1(FIG. 11) and the pixel of view N will appear to occupy the entire widthof lenticle 202A (FIG. 2). When pixel 216A is displaying pixels of otherviews, the deflection of view multiplexers 204A-B cause the eye to seeflat black mask 214. However, the persistence of vision causes viewer 10to continue to see the pixel of view N at location 216A1 (FIG. 11) forfour (4) 240 Hz cycles.

In the next 240 Hz cycle (FIG. 4), view multiplexer 204A switches on.The cumulative deflection of view multiplexers 204A-B is 0.5 degrees,and pixel 216A appears to be at location 216A3 (FIG. 11) and displays apixel of view N+2 (FIG. 4) for a single refresh cycle. If an eye ofviewer 10 is 0.5 degrees from being aligned with pixel 216A through mask214 and lenticle 202A, that eye will see view N+2 of pixel 216A and thepixel of view N+2 will appear to occupy the entire width of lenticle202A. Mask 214 and the persistence of vision cause viewer 10 to continueto see the pixel of view N+2 at location 216A3 (FIG. 11) for four (4)240 Hz cycles as described above.

In the next 240 Hz cycle (FIG. 4), view multiplexer 204B switches on.The cumulative deflection of view multiplexers 204A-B is 0.75 degrees,and pixel 216A appears to be at location 216A4 (FIG. 11) and displays apixel of view N+3 (FIG. 4) for a single refresh cycle. If an eye ofviewer 10 is 0.75 degrees from being aligned with pixel 216A throughmask 214 and lenticle 202A, that eye will see view N+3 of pixel 216A andthe pixel of view N+3 will appear to occupy the entire width of lenticle202A. Mask 214 and the persistence of vision cause viewer 10 to continueto see the pixel of view N+3 at location 216A4 (FIG. 11) for four (4)240 Hz cycles as described above.

In the next 240 Hz cycle (FIG. 4), view multiplexer 204A switches off.The cumulative deflection of view multiplexers 204A-B is 0.25 degrees,and pixel 216A appears to be at location 216A2 (FIG. 11) and displays apixel of view N+1 (FIG. 4) for a single refresh cycle. If an eye ofviewer 10 is 0.25 degrees from being aligned with pixel 216A throughmask 214 and lenticle 202A, that eye will see view N+1 of pixel 216A andthe pixel of view N+1 will appear to occupy the entire width of lenticle202A. Mask 214 and the persistence of vision cause viewer 10 to continueto see the pixel of view N+1 at location 216A2 (FIG. 11) for four (4)240 Hz cycles as described above.

In the next 240 Hz cycle (FIG. 4), view multiplexer 204B switches off.The cumulative deflection of view multiplexers 204A-B is 0 degrees, andpixel 216A again displays a pixel of view N and appears to be atlocation 216A1 (FIG. 11) for a single refresh cycle. And, the four (4)cycle pattern of timing diagram 400 (FIG. 4) repeats.

Thus, view multiplexers 204A-B time-multiplex pixels 216A-F such thateach pixel can display a pixel of four (4) different views ofautostereoscopic display 100. It should be appreciated that, withoutlenticles 202A-C, pixel 216A would appear to a human viewer to be four(4) distinct pixels at locations 216A1 (FIG. 11), 216A2, 216A3, and216A4. Thus, without a lenticular array or other view selector, viewmultiplexers 204A-B cause a display to have an apparent resolution thatis much more dense than the physical resolution of the display.

It should also be appreciated that there are alternatives to alenticular array to ensure that a human viewer sees only one of themultiple views of an autostereoscopic image. For example, a parallaxbarrier can be used. In addition, using lasers rather than LCDs or LEDsas light sources allow the individual views displayed by a particularpixel to be only visible at locations to which the laser's light isdirected.

As shown in FIG. 2, autostereoscopic display 100 includes a number oflenticles 202A-C of a lenticular array. In this illustrative embodiment,lenticles 202A-C are designed to provide a relatively flat field. Otherapproaches to minimize lenticle focus errors due to curvature of fieldsare described below.

View multiplexers 204A-B are immediately behind the lenticular array inthis illustrative embodiment. View multiplexers 204A-B are described inmore detail below in conjunction with FIG. 3. Behind view multiplexers204A-B is a layer 206 of transparent material such as plastic, glass, ora gas such as air, a polarizer 208, and a second layer 210 oftransparent material.

Behind layer 210 is an array of color filters 212A-F, each of whichimparts a red, green, or blue hue to a respective one of pixels 216A-F.Pixels 216A-F are vertical pixels.

Mask 214 is positioned between color filters 212A-F and pixels 216A-Fand limits the perceived width of pixels 216A-F to about one-quartertheir actual width, leaving dark space between pixels 216A-F forapparent pixels due to light deflection by operation of viewmultiplexers 204A-B. In this illustrative embodiment, the field of focusof lenticles 202A-C is at about mask 214.

Pixels 216A-F are positioned immediately behind mask 214. Each of pixels216A-F is a single, independently controlled LCD sub-pixel, having itsown independently controlled display intensity. The color of each ofpixels 216A-F is controlled by a respective one of color filters 212A-F.Behind pixels 216A-F is another layer 218 of transparent material and apolarizer 220. Behind polarizer 220 is a light source (not shown) as istypical in conventional LCD displays. Polarizers 208 and 220 are similarto polarizers used in conventional LCD displays.

View multiplexer 204A is shown in greater detail in FIG. 3. Except asotherwise noted herein, view multiplexer 204B is directly analogous toview multiplexer 204A and the following description is also applicableto view multiplexer 204B.

View multiplexer 204A (FIG. 3) is shown in cross-section view from aboveand includes triangular columns 304A-C of birefringent material such asliquid crystal. Triangular columns 304A-C are positioned between a layer302 of transparent plastic or glass and a grooved layer 306 oftransparent plastic or glass into which triangular grooves are made toprovide space for triangular columns 304A-C.

Behind layer 306 is a switch layer 310 of liquid crystal betweenelectrode layers 308 and 312. By selectively applying a charge toelectrode layers 308 and 312, polarization of light passing throughswitch layer 310 can be switched, e.g., between parallel andperpendicular orientations relative to the birefringent material intriangular columns 304A-C.

The birefringent material, its orientation set at manufacture, and thesize and shape of triangular columns 304A-C are selected to provide oneamount of light deflection with one polarization orientation of switchlayer 310 and a different amount of deflection with the otherpolarization orientation of switch layer 310. In effect, thebirefringent material in triangular columns 304A-C are prisms whosedegree of light deflection vary according to the state of switch layer310.

In this illustrative embodiment, the birefringent material is selectedto have one refraction index substantially equal to the refraction indexof the transparent material of layers 302 and 306, and thereforeprovides no deflection of light as shown by arrow 314A, for onepolarization orientation of switch layer 310. In effect, the prisms oftriangular columns 304A-C disappear into layers 302 and 306, andtriangular columns 304A-C and layers 302 and 306 appear to be a single,flat layer of transparent material. However, it should be appreciatedthat it is not necessary that the prisms provide a deflection of zerodegrees to effectively disappear into layers 302 and 306. As long as theprisms are controllable to provide one of at least two different anglesof deflection, pixel 216A can be made to appear in one of at least twodifferent, perhaps overlapping, locations and thus serve the purpose oftime-multiplexing of pixel 216A.

For the other polarization orientation of switch layer 310 in thisillustrative embodiment, the birefringent material, its orientation setat manufacture, and the size and shape of triangular columns 304A-C inview multiplexer 204A are selected to deflect light by 0.5 degrees asshown by arrow 314B, and the birefringent material, its orientation setat manufacture, and the size and shape of triangular columns 304A-C inview multiplexer 204B are selected to deflect light by 0.25 degrees. Ineffect, the different refraction index of the birefringent material withthis polarization orientation and the dimensions of triangular columns304A-C are prisms designed to reflect light by a predetermined desiredangle, such as 0.5 degrees in view multiplexer 204A and 0.25 degrees inview multiplexer 204B in this illustrative embodiment.

As described above, autostereoscopic display 100 includes a number oflenticles 202A-C that are designed to provide a relatively flat field.Another approach to reducing autostereoscopic image degradation due tocurvature of field of conventional lenticles is illustrated by FIGS. 5and 6.

Viewers 10 (FIG. 5) are viewing an autostereoscopic image displayed byautostereoscopic display 100B from various viewing angles.Autostereoscopic display 100B is an alternative embodiment to that ofautostereoscopic display 100 and is directly analogous toautostereoscopic display 100 except as otherwise described herein.Autostereoscopic display 100B does not include meniscus-cylinderlenticles but instead includes lenticles of a more conventional design,having a convex proximal surface and a flat distal surface.

An autostereoscopic image is best viewed in very good focus. In the caseof autostereoscopic display 100B, the focus target is mask 214B.However, viewing angles that stray significantly from directlyperpendicular to autostereoscopic display 100B tend to be out of focusdue to the curvature of field of some lenticles. This curvature of fieldis illustrated by curved line 502, which represents the locus of foci ofthe lenticle at various angles of perspective. To reduce loss of focusover a wider range of viewing angles, the lenticular array ofautostereoscopic display 100B are focused slightly behind mask 214B toprovide loci of focus along curved line 504.

A portion of autostereoscopic display 100B is enlarged in FIG. 6. Curvedlines 502 and 504 are exaggerated to illustrate the focus errorstherein.

Curved line 502 represents loci of focus provided by a lenticle in atypical conventional autostereoscopic display. Curved line 502 shows avery good focus, i.e., near zero focus error, for straight-on viewingangles, i.e., perpendicular to autostereoscopic display 100B. At a widerviewing angles, curved line 502 shows a noticeable focus error 602.

In this illustrative embodiment, lenticles of autostereoscopic display100B are designed to focus behind mask 214B for straight-on viewingangles. As shown in FIG. 7, curved line 504 is behind mask 214B by anamount that, from viewing perspectives near perpendicular to mask 214,the focus of lenticles of autostereoscopic display 100B are blurred by awidth 702 that is no more than the width of the gaps in mask 214B. Suchlimited blurring does not affect the accuracy of the autostereoscopicimage perceived by viewer 10 because nothing other than the intendedpixel is viewable to viewer 10 through each lenticle. Thus, the focuserror 604 (FIG. 6) viewable at near perpendicular viewing angles issufficiently small to not affect the perception of focus of viewer 10.

At wider viewing perspectives, curved line 504 intersects mask 214B toprovide very good focus, yet no better than that perceivable by viewer10 at near perpendicular viewing angles, and begins to blur at evenwider viewing perspectives as curved line 504 is in front of mask 214B.The quality of view as perceived by viewer 10 is preserved at thesewider viewing perspectives up to a focus error 606, beyond which theamount of blurring exceeds the width of gaps in mask 214B.

In some embodiments, maintaining focus errors no wider than gaps in mask214B might allow for unacceptably large focus errors at wider angles ofviewing perspective. Generally, best results are achieved by determiningthe width of blur over a range of viewing angles for which qualityviewing is desired and selecting a lens and locus of foci whose width ofblur is minimized over that range of viewing angles.

The result is that lenticles whose locus of foci are represented bycurved line 504 provide a much wider range of acceptable viewing anglesthan do conventional lenticles.

As described briefly above, a single view multiplexer 804 (shown incross section view in FIG. 8) can sweep across a range of deflectionangles to provide a number of views from a single pixel.

View multiplexer 804 includes triangular columns 808A-C of a materialwhose refraction index is controllable, e.g., by an electrical field. Anexample of such a material is liquid crystal. Triangular columns 808A-Care positioned between a layer 606 of transparent plastic or glass and agrooved layer 810 of transparent plastic or glass into which triangulargrooves are made to provide space for triangular columns 808A-C.

In front of layer 806 is an electrode layer 802. Behind layer 810 is anelectrode layer 812. By selectively applying a charge to electrodelayers 802 and 812, the refraction index of the material in triangularcolumns 808A-C can be varied.

The material within triangular columns 808A-C, its orientation set atmanufacture, and the size and shape of triangular columns 808A-C areselected to provide a desired range of deflection across the range ofelectrical fields that can be produced across electrode layers 802 and812. In effect, the material in triangular columns 808A-C are prismswhose degree of light deflection vary according to the electrical fieldbetween electrode layers 802 and 812.

In this illustrative embodiment, the desired range of deflection is0.0-2.0 degrees, the material within triangular columns 808A-C has arefraction index that varies from the refraction index of layers 806 and810 to 0.1 above the refraction index of layers 806 and 810, andtriangular columns 808A-C have a cross-sections that are right triangleswith an angle 816 of 20 degrees.

Timing diagram 900 (FIG. 9) illustrates the time-multiplexing of pixel216A using view multiplexer 804. Timing diagram 900 shows an electricalfield between electrode layers 802 and 812, the corresponding angle ofdeflection of view multiplexer 804, and various views displayed by pixel216A. The angle of deflection provided by view multiplexer 804 sweepsthrough a predetermined range, e.g., 0-2.0 degrees. Pixel 216A displayspixels of views N through N+3 in a synchronized manner such that pixel216A displays a pixel of view N while view multiplexer 804 sweepsthrough deflection angles 0.0-0.5 degrees, displays a pixel of view N+1while view multiplexer 804 sweeps through deflection angles 0.5-1.0degrees, displays a pixel of view N+2 while view multiplexer 804 sweepsthrough deflection angles 1.0-1.5 degrees, and displays a pixel of viewN+3 while view multiplexer 804 sweeps through deflection angles 1.5-2.0degrees, after which view multiplexer 804 returns to provide adeflection of 0 degrees and pixel 216A displays a pixel of the nextframe of view N.

It should be appreciated that, while pixel 216A is shown totime-mulitplex only four (4) views, pixel 216A can time-multiplex manymore views, limited only by the switching rate of pixel 216A relative toa desired frame rate. In embodiments in which pixel 216A is implementedusing one or more LEDs, e.g., in very large signage, pixel 216A canswitch much more rapidly than an LCD pixel and can time-multiplex manymore views. For example, some LEDs can switch at frequencies of 2.0 MHz.Accordingly, a single LED (or a cluster of red, green, and blue LEDs)can provide 300 or more views of single pixel, limited only by theoptical quality of lenticles 202A-C and the range of deflection anglesand switching speed of view multiplexer 804.

Timing diagram 1000 (FIG. 10) shows an alternative manner in which viewmultiplexer 804 can time-multiplex pixels of multiple views shown bypixel 216A. Once view multiplexer 804 sweeps through a range ofdeflection angles, e.g., 0-2.0 degrees, view multiplexer 804 sweeps backthrough the range in reverse direction, e.g., from 2.0 degrees to 0degrees. In a synchronized manner, once pixel 216A switches throughpixels of views N, N+1, N+2, and N+3, pixel 216A switches through pixelsof a subsequent frame in reverse order, i.e., through views N+3, N+2,N+1, and N.

If should be appreciated that view multiplexer 804 can cycle throughangles of deflection in other ways, including stepped patterns. Inaddition, multiple instances of view multiplexer 804 can be stacked asare view multiplexers 204A-B (FIG. 2) to provide greater ranges ofcumulative deflection angles.

The view multiplexer may also be used for purposes not involvingautostereo, and most, but not all, of the same basic technology makespossible additional applications. Using the view multiplexer without alenticular lens, but in precisely the same manner as described herein,will result in a normal two-dimensional image with increased pixeldensity. Also, by using a prism structure within the device that has asteeper slope, and thus a wider angle of deflection, and also using thedevice without a lenticular lens, it may be used for the purpose ofcreating a projected image with a wider field of view (i.e. theadditional multiplicity of pixels would be used to extend the image toeither the left or the right of the original, underlying display), or ofcreating two projected images running in time sequence from the samedisplay (such as to show a right and a left view, positioned somedistance apart, for two-view stereo viewing in a head-mounted near-eyedisplay). In conjunction with a camera, similar effects may be attainedin capturing a wider field of view or multiple views. By placing theview multiplexer in line with a camera or projector, or with the nakedeye, images can be captured or displayed having characteristics greaterthan those captured or displayed solely by the camera or projector.Example characteristics include a wider field of view, increased pixeldensity, adjusted diffraction characteristics, correction of pixelpositioning in underlying displays, adjusted focus, and the like.

As a first example, a camera or projector, or a simple beam of light,may have a predefined field of view or projection. For example, a cameramay have a field of view of 35 degrees, 50 degrees, 100 degrees, or thelike. The system may generate an image having a greater field of view byadjusting an angle of the view multiplexer and then capturing the imageor view when the angle of the view multiplexer is adjusted. For example,the angle of the view multiplexer may be adjusted to an angle such thatthe image sensor of the camera is aimed straight ahead, but the imagecenter that is captured is of a scene 45 degrees from objects which areperpendicular to (i.e. directly in front of) the image sensor. In thisway, the view multiplexer functions as a kind of periscope. When themultiple views of the view multiplexer, at different angles, aresynchronized with multiple camera exposures, the camera may take aseries of pictures which may be used as slices of an overall image witha much larger field of view than is otherwise possible to capture with asingle sensor. In another application, the overall field of view createdby multiple captures synchronized to changed angles of the viewmultiplexer may remain within the total field of view that might becaptured by a lens unaided by the view multiplexer, but the picture thuscreated by stitching together multiple images captures with the aid ofthe view multiplexer will contain a multiplied image resolution, orpixel density, than otherwise attainable. This application is exactlyanalogous to the increased pixel density for the application ofautostereo display already detailed. Thus a camera would be capable,with the aid of the view multiplexer, of generating images that can bezoomed in on electronically, without resolution loss.

The system can also take multiple images where the view multiplexer isadjusted to different angles during each exposure or image capture. Thesystem may automatically identify the appropriate angle. For example, auser may indicate that a picture having a particular field of view isdesired. The system may then calculate the angles of the viewmultiplexer to generate the image having the desired field of view. Whenthe user or system activates the shutter of the camera, the system mayadjust the angle of the view multiplexer to cause each image or exposureto have different fields of view, based on the deflection position ofthe view multiplexer. As before, the deflection position may include adeflection position that is past the field of view or focus of thecamera. Once the necessary or desired number of images is captured, thesystem can stitch the images together to generate a single image havinga field of view wider than the field of view of the camera.

A similar system can be incorporated with a projector, or with anyunderlying display to be used to generate images to be presented at somedistance from the display, such as in near-eye displays using waveguideto carry images from displays located at some distance and/or a normallyunviewable angle from the eyes. In such a system the view multiplexerwould be coupled to the projector or underlying display. As theprojector or display shows images, the view multiplexer could sweepimages across a wide range of positions creating a video showing imageswith a wider field of view than typical. For example, the angle of theview multiplexer could be synchronized with the playing of the images ofthe projector/underlying display. As the projector or display displayednew images, the view multiplexer would sweep across a plurality ofdeflection angles to show each of the images at different angles,thereby creating the effect that each image has a field of view greaterthan what could typically be displayed. More than one view multiplexercould be stacked to increase the maximum sweep angle of the system. Forexample, if each view multiplexer could sweep across a 2 degree range,two multiplexers stacked could sweep across a 4 degree range. Also, theangles of deflection of the prisms located within the view multiplexer,as already detailed, could be increased to attain the same greater rangeas might be achieved with more than one stacked view multiplexer. Thecombination of greater angles of deflection in a given stacked viewmultiplexer, and multiple stacked view multiplexers, would allow for asystem displaying up to 360 degrees.

Such a system would also be capable of showing alternating left andright eye views to vantage points appropriate to each eye, from a singleunderlying display, such that stereo is perceived. Equally, if afield-sequential color display is the image source, or other data areextracted from a single image, the system would be capable of showingred. Green and blue signals (in the case of a field sequential display)or specialized image data (such as a depth map, or a luminance signal,for two examples), could thus be sent to different viewing locations.

As another example, the predefined characteristic of a camera captureservice may include a pixel density. In other words, the camera may havea set pixel density that images are captured at. The view multiplexercould increase the total pixel density of the captured images, resultingin an image that could be zoomed in on without a decrease in theresolution of the image. The view multiplexer may be synchronized withthe system such that 2, 4, or more horizontal or vertical pixels arecreated in the space normally allotted to one pixel. This is similar tothe technique discussed above where a single physical pixel issubdivided into subpixels. To accomplish this effect, the system wouldtake two or more images in rapid succession. Each of the images would beat a slightly different view multiplexer deflection angle, resulting intwo images that were very similar with a very slight different inviewing angle.

The system can then stitch together the images to generate a singleimage. The system can take image information from each of the capturedimages to fill in information between two original pixels. As anexample, using only the camera, the image may include Pixel A and PixelB. By capturing the two images at slightly different angles, the systemcan fill in the information between the Pixel A and Pixel B. Thus, thesystem divides each of the original pixels into sub-pixels and fills inthe information for the sub-pixels using information obtained from themultiple captured images. The resulting image has a greater resolutionthan the pixel count of the imager of the camera.

As before, a similar system can be used with a projector to displayimages having a greater pixel density. This system would be similar tothose discussed before with respect to the flat panel displays (e.g.,televisions, billboards, etc.). However, rather than being attached to aflat panel display, this system would be attached to a projector. Thus,the light from the projection would go through the view multiplexer witha small sweep in angles to increase the pixel density of the imagedisplayed to a viewer. This can also be used to display anautostereoscopic image to the viewers.

In another example, the desired effect may include specific diffractioncharacteristics. The prism structure within the view multiplexer, asdescribed herein, is actually a commonly defined blazed diffractiongrating. Application of voltage to the liquid crystal material canchange the effective slope, height, and/or periodicity of the prismarray. This may be done to adjust the diffraction effect so as to limitit when diffraction is unwanted, or to emphasize it when diffraction isdesired. Specifically applied voltage may also be used to change thediffraction effect in time with the changing images presented by anunderlying display. For example, a field sequential display may be usedto present successive images that are green, red and blue. The viewmultiplexer may be synchronized with each color such that it grates forthe wavelength of each color in sequence, in order to pass those colorsthrough an optical waveguide, or for other applications.

Similarly, the adjustability may be deployed to correct for inaccuratelymanufactured plastic or glass gratings. This would be accomplished byapplying differential voltage to different areas of the prism array, asrequired to create a uniform array.

Similarly, differential voltage may be applied to different areas of theview multiplexer to correct for inaccurate pixel alignment in anunderlying display—as is typical in displays assembled from multiplemodules.

Similarly, the adjustable diffraction grating made possible by changedvoltage in the view multiplexer may be used in conjunction with acamera. As the grating frequency and amplitude are adjusted fordifferent diffractions, and are calibrated for specific light sources(such as the flash built into the camera, or such as an ultra-violetlight), the camera can be turned into a spectrometer for sensing gasleaks, color calibrating printers, diagnostics for skin ailments, andthe like. In this case, the multiplexer would not need to be closelysynchronized with the shutter of the camera, but merely to be runningwhile the shutter is open. In this case, the diffraction setting (i.e.,the voltage of the multiplexer) would be set to operate while the camerashutter is open, and then change to other settings, as required, whenthe shutter may be open again in order to measure other phenomena.

In another use case, differential adjustment of applied voltage todifferent areas of the view multiplexer can allow it to be used as afocusing lens. An original form of a focusing lens may be designed intothe molded or etched prism structure made of plastic or glass that isenclosed within the liquid crystal cell, typically taking the form of aFresnel pattern so that the prisms may be of uniform enough, and shortenough, size so as to fit within the maximum usable cell gap. The liquidcrystal prism structures thus bounded by this plastic or glass structuremay then have its shape adjusted by voltage so as to change theprescriptive characteristics of the lens. This adjustment may bepermanent (whenever voltage is applied, an may also be adjustable,either in a synchronized sequence with information to be viewed, or toadjust the lens for different viewers and different viewing conditions.

The above description is illustrative only and is not limiting. Thepresent invention is defined solely by the claims which follow and theirfull range of equivalents. It is intended that the following appendedclaims be interpreted as including all such alterations, modifications,permutations, and substitute equivalents as fall within the true spiritand scope of the present invention.

What is claimed is:
 1. A system, comprising: a camera capturing imageshaving predefined characteristics; a view multiplexer attached to thecamera, wherein the view multiplexer enhances at least one of thepredefined characteristics of the camera at a time interval, wherein thepredefined characteristic comprises at least one of: a field of view ofthe camera, a diffraction characteristic, a pixel density, and afocusing effect, wherein the enhanced characteristic creates a widerfield of view, wherein the view multiplexer comprises a lens of thecamera, wherein the view multiplexer is synchronized with a shutter ofthe camera; at least one processor operatively coupled to the camera andview multiplexer; and a memory storing instructions executable by theprocessor to: adjust an angle of the view multiplexer to show one ormore pixels at the time interval causing the user to see the one or morepixels in a location corresponding to the one or more pixels beingshown, wherein the one or more pixels being shown is based upon the timeinterval; and capture, using the camera in conjunction with the viewmultiplexer having the adjusted angle at the time interval, at least oneimage having at least one enhanced characteristic, wherein the image iscaptured through the view multiplexer.
 2. The system of claim 1, whereinto adjust the angle of the view multiplexer comprises adjusting avoltage of the view multiplexer.
 3. The system of claim 1, wherein toadjust an angle of the view multiplexer comprises adjusting a deflectionposition past a focus field of the camera.
 4. The system of claim 1,wherein to capture comprises capturing a plurality of exposures whereineach of the plurality of exposures comprises a different angle of theview multiplexer.
 5. The system of claim 4, further comprising togenerate a panoramic image by stitching the plurality of exposurestogether.
 6. The system of claim 1, wherein one of the predefinedcharacteristics comprises a pixel density and wherein the viewmultiplexer increases the pixel density.
 7. The system of claim 6,wherein to capture comprises capturing a plurality of images insuccession, each of the images having a view multiplexer angle differentfrom the image previously captured.
 8. The system of claim 7, furthercomprising to generate an image having an increased pixel density bystitching the plurality of images together.
 9. The system of claim 1,wherein the camera comprises a camera integral to a user electronicdevice.
 10. The system of claim 1, wherein the enhancing a diffractioncharacteristic comprises the view multiplexer increases, decreases orotherwise adjusts a diffraction effect.
 11. The system of claim 1,wherein the enhancing a focusing effect comprises the view multiplexeradjusts a focusing effect.
 12. A method, comprising: capturing, using acamera in conjunction with a view multiplexer attached to the camera, atleast one exposure at a time interval, wherein the exposure comprises aview having a field of view wider than a field of view of the camera,wherein the view multiplexer comprises a lens of the camera, wherein theview multiplexer is synchronized with a shutter of the camera; whereinthe capturing comprises: identifying a focus field of the camera;adjusting an angle of the view multiplexer to show one or more pixels atthe time interval causing the user to see the one or more pixels in alocation corresponding to the one or more pixels being shown, whereinthe one or more pixels being shown is based upon the time interval,wherein the angle of the view multiplexer comprises a deflectionposition past the focus field of the camera, wherein the predefinedcharacteristic comprises at least one of: a field of view of the camera,a diffraction characteristic, a pixel density, and a focusing effect,wherein the enhanced characteristic creates a wider field of view; andcapturing the at least one exposure with the view multiplexer at theadjusted angle at the time interval, wherein the at least one exposureis captured through the view multiplexer.
 13. The method of claim 12,wherein the at least one exposure comprises a plurality of exposures andwherein each of the exposures comprises an exposure where the viewmultiplexer is at a different angle.
 14. The method of claim 13,comprising generating a panoramic image by stitching the plurality ofexposures together.